thanks for the tips everyone. bad news is my bike is nothing like an e-zip when it comes to the battery. here's a link to a picture. my bike is just like this one http://www.leys.com/basic/rockfish/images/eride.jpg
good news, it turned out to be even easier to fix. the lock thing i was talking about is right under the handle of the battery pack, if you can make that out. well the locking thing is a really weird little cylinder with knobbles and stuff, seems to have been machined and made just for this model. seems pretty pointless, so i just drilled out the back of the lock on the frame, and replaced the whole situation with a bolt and wing nut. thanks again for trying to help, though, guys.